Standard and
Professional Editions of MailEnable store details
in TAB delimited files. Because this file can be updated by multiple applications
(e.g.: Administration Program, web administration, Control Panels, etc), MailEnable
implements its own means of locking files to ensure data integrity. Hence, when
updates to these files are required the system performs the following actions:

Creates a BLK file to notify
other applications/agents that a file needs to be updated.

Once all file access has been blocked, the
required changes are recorded to a TMP file.

This file is then renamed to a .TAB
file.

Finally, the .BLK file is removed by the caller. Each of these operations will be
re-tried for up to a minute if they cannot be executed. Hence if
a calling process has crashed or failed when it was attempting to update
the file, the .BLK file is left resident. This will obviously
cause problems with Administration. To resolve this, search under the Mail Enable\Config directory
for .BLK files and remove them. It is also important to identify any
applications that may have the file locked. For example, if one of the .TAB
files is opened in Excel, MailEnable will be unable to update it. Also, ensure
that you have authenticated with an account that has full access
to the C:\Program Files\Mail Enable\Config directory and its sub directories, and
that the all the files under this directory are not Read Only protected (i.e.
ensure that MailEnable can update the TAB files under the CONFIG
directory).